Transporters

  • Article
    | Open Access

    The presence of the gene encoding the solute binding protein TphC has been shown to permit the uptake of terephthalate (TPA), which is the breakdown product of Polyethylene terephthalate (PET) plastic. Here the authors present a structural characterization of TphC in both open and TPA-bound closed conformations.

    • Trishnamoni Gautom
    • , Dharmendra Dheeman
    •  & Neil Dixon
  • Article
    | Open Access

    Iron is an essential plant nutrient that is poorly bioavailable in alkaline soils, resulting in reduced agricultural productivity. Here, the authors report the synthesis of stable and cheap iron-chelator, proline-2’-deoxymugineic acid (PDMA), and demonstrate its utility as potential fertilizer.

    • Motofumi Suzuki
    • , Atsumi Urabe
    •  & Kosuke Namba
  • Article
    | Open Access

    In Bacteroidetes, SusCD complexes mediate uptake of large nutrients across the outer membrane. SusCD structures in the apo state and in complex with β2,6 fructo-oligosaccharides reveal several substrate molecules in the binding cavity and suggest details of the pedal bin mechanism employed in glycan import.

    • Declan A. Gray
    • , Joshua B. R. White
    •  & Bert van den Berg
  • Article
    | Open Access

    Osh6p and Osh7p are yeast lipid transfer proteins (LTPs) that must transiently interact with membranes but how they escape from the electrostatic attraction of the plasma membrane is unclear. Here authors show that Osh6p reduces its avidity for anionic membranes once it captures PS or PI4P, due to a molecular lid closing its lipid-binding pocket.

    • Nicolas-Frédéric Lipp
    • , Romain Gautier
    •  & Guillaume Drin
  • Article
    | Open Access

    Bats possess an extended lifespan compared to most mammals of their size, and have a low cancer incidence. Here the authors show that several bat species exhibit resistance to genotoxic agents that is in part attributable to high expression of the ABCB1 transporter.

    • Javier Koh
    • , Yoko Itahana
    •  & Koji Itahana
  • Article
    | Open Access

    Acyl carrier proteins (ACPs), a universal and highly conserved carrier of acyl intermediates during fatty acid and polyketide synthesis, are difficult to visualise. Here, the authors developed a facile, Raman spectroscopy-based method to detect ACP-substrate interactions.

    • Samuel C. Epstein
    • , Adam R. Huff
    •  & Louise K. Charkoudian
  • Article
    | Open Access

    P-glycoprotein, an ATP-binding cassette (ABC) transporter, extrudes a large variety of xenobiotics from the cell which protects tissues from toxins. Here authors solve a pair of X-ray structures of homodimeric P-glycoprotein and resolve structural elements proposed to participate in the mechanism of the transporter.

    • Atsushi Kodan
    • , Tomohiro Yamaguchi
    •  & Hiroaki Kato
  • Article
    | Open Access

    Secondary transporters catalyse substrate translocation across the cell membrane but the role of lipids during the transport cycle remains unclear. Here authors used hydrogen-deuterium exchange mass spectrometry and molecular dynamics simulations to understand how lipids regulate the conformational dynamics of secondary transporters.

    • Chloe Martens
    • , Mrinal Shekhar
    •  & Argyris Politis
  • Article
    | Open Access

    The noradrenergic system plays numerous physiological roles but tools to study it are scarce. Here the authors develop a fluorescent analogue of norepinephrine that can be used to label noradrenergic neurons and the synaptic vesicles, and use it to measure single synaptic vesicle release sites in living mice.

    • Matthew Dunn
    • , Adam Henke
    •  & Dalibor Sames
  • Article
    | Open Access

    Na+-coupled acid-base membrane transport proteins regulate blood pressure, ion homeostasis and acid-base chemistry. Here the authors present the 3.9 Å resolution cryoEM structure of the sodium-bicarbonate cotransporter NBCe1 and characterize its ion coordination site and ion accessibility pathway with mutagenesis experiments.

    • Kevin W. Huynh
    • , Jiansen Jiang
    •  & Ira Kurtz
  • Article
    | Open Access

    Multidrug efflux pumps significantly contribute for bacteria resistance to antibiotics. Here the authors present the structure of Campylobacter jejuni CmeB pump combined with functional FRET assays to propose a transport mechanism where each CmeB protomers is functionally independent from the trimer.

    • Chih-Chia Su
    • , Linxiang Yin
    •  & Edward W. Yu
  • Article
    | Open Access

    The outer mitochondrial membrane translocator protein (TSPO) mediates several mitochondrial functions and binds cholesterol with a high affinity. Here the authors use solid-state NMR to show that cholesterol binding to TSPO results in allosteric changes that modulate TSPO oligomerization.

    • Garima Jaipuria
    • , Andrei Leonov
    •  & Markus Zweckstetter
  • Article
    | Open Access

    Sulfonates are a major source of sulphur for soil microbes but their cellular uptake is still not fully understood. Here the authors show thatSaccharomyces cerevisiae YIL166C(SOA1)encodes for an inorganic sulphur transporter that can also function as a sulfonate and choline sulphate transporter.

    • Sylvester Holt
    • , Harish Kankipati
    •  & Johan M. Thevelein
  • Article
    | Open Access

    Pannexins are oligomeric plasma membrane channels that allow permeation of ions and large molecules. Here the authors show that human Pannexin 1 activation is a multistep event, where modification of each monomer opens the channel to a unique conductance state and fine tunes its activity.

    • Yu-Hsin Chiu
    • , Xueyao Jin
    •  & Douglas A. Bayliss
  • Article
    | Open Access

    ATP-binding cassette (ABC) transporters hydrolyse ATP to transport molecules across the cell membrane. Here Vogelet al. show that the ABC exporter MsBA can couple ATP hydrolyse to an adenylate kinase activity that seems to be predominant at low ATP levels and a general feature of ABC exporters.

    • Hundeep Kaur
    • , Andrea Lakatos-Karoly
    •  & Clemens Glaubitz
  • Article
    | Open Access

    In neurons and glia, glutamate transporters catalyse the reuptake of this neurotransmitter by coupling it with cation transport. Here the authors combine X-ray crystallography and molecular dynamics simulations of the archeal glutamate transporter GltTkto get insight into the coupled transport mechanism.

    • Albert Guskov
    • , Sonja Jensen
    •  & Dirk Jan Slotboom
  • Article
    | Open Access

    Pathogenic bacteria acquire iron from heme cofactors imported by ABC heme transporters. Here the authors present crystal structures of Burkholderia cenocepaciaheme importer BhuUV with and without the heme-binding protein BhuT, gathering mechanistic insight into the catalytic cycle of heme import.

    • Youichi Naoe
    • , Nozomi Nakamura
    •  & Hiroshi Sugimoto
  • Article
    | Open Access

    The neurotransmitter transporter SERT counter transport K+ to transport serotonin. Here the authors show that the activity of the prokaryotic orthologue LeuT is also modulated by this cation, suggesting a general regulatory role for K+on neutrotrasmitter:sodium symporters function.

    • Christian B. Billesbølle
    • , Jonas S. Mortensen
    •  & Claus J. Loland
  • Article
    | Open Access

    ABC exporters mediate the translocation of cytotoxic compounds to the cell exterior via ATP hydrolysis. Here, the authors show that the bacterial transporter MsbA requires additional energy from the transmembrane electrochemical proton gradient to facilitate drug transport.

    • Himansha Singh
    • , Saroj Velamakanni
    •  & Hendrik W. van Veen
  • Article
    | Open Access

    Organic cation transporters are important drug transporters that influence therapeutic outcomes. Here, the authors find that these transporters are regulated by tyrosine phosphorylation and propose that tyrosine kinase inhibitors can influence drug transporter function through post-translational mechanisms.

    • Jason A. Sprowl
    • , Su Sien Ong
    •  & Navjotsingh Pabla
  • Article
    | Open Access

    Iron export from vertebrate cells is mediated by ferroportin, which is suppressed by the peptide hormone hepcidin. Taniguchi et al. present crystal structures of a putative bacterial ferroportin homologue in both outward- and inward-facing states, providing insight into its transport mechanism.

    • Reiya Taniguchi
    • , Hideaki E. Kato
    •  & Osamu Nureki
  • Article
    | Open Access

    Insects can accumulate high levels of glycerol as an adaptive response to dessication and freezing. Here, the authors show that glycerol transporters evolved from water-selective channels that co-opted the glycerol transport function of ancestral aquaglyceroporins in the oldest lineages of insects.

    • Roderick Nigel Finn
    • , François Chauvigné
    •  & Joan Cerdà
  • Article |

    The two-partner secretion system transports proteins across the bacterial outer membrane but the molecular mechanisms involved are poorly understood. Here, Baud et al. use site-specific crosslinking to track the path of a protein substrate through the β-barrel of its Omp85 transporter.

    • Catherine Baud
    • , Jérémy Guérin
    •  & Françoise Jacob-Dubuisson
  • Article |

    Secondary multidrug transporters use ion concentration gradients to power the removal of drug molecules from cells. Here, Fluman et al. demonstrate that the bacterial transporter MdfA can catalyse the efflux of divalent cations in two consecutive transport cycles where each charged moiety is transported as if it were a separate substrate.

    • Nir Fluman
    • , Julia Adler
    •  & Eitan Bibi
  • Article
    | Open Access

    Glucose transporters are a medically important class of membrane proteins often deregulated in diseases such as Type 2 diabetes. Here, Wisedchaisri et al. report the crystal structure of XylE in an inward-facing open conformation to provide a general mechanism of substrate transport for the sugar porter family of proteins.

    • Goragot Wisedchaisri
    • , Min-Sun Park
    •  & Tamir Gonen
  • Article |

    The flow of calcium into the mitochondrial matrix is mediated by the mitochondrial calcium uniporter. Fieniet al. apply patch-clamp techniques to mitoplasts isolated from different mouse and Drosophilatissues and find that the mitochondrial calcium uniporter activity varies depending on the tissue studied.

    • Francesca Fieni
    • , Sung Bae Lee
    •  & Yuriy Kirichok
  • Article
    | Open Access

    Flavodoxin requires tight binding of its FMN cofactor to be active, but the residues involved are unknown. In this biophysical study, FMN binding is shown to change from nanomolar to picomolar affinity on extremely slow protein relaxation and the residues responsible for cofactor binding are identified.

    • Yves J.M. Bollen
    • , Adrie H. Westphal
    •  & Carlo P.M. van Mierlo
  • Article
    | Open Access

    In mammalian cells, ABC transporter proteins were thought to exclusively export a range of substrates out of cells. Quazi and colleagues show that, in retinal photoreceptor cells, ABCA4 is acting as an importer of phospholipids and that mutations known to cause Stargardt disease decrease its activity.

    • Faraz Quazi
    • , Stepan Lenevich
    •  & Robert S. Molday